The invention relates to an apparatus for treating dough, in particular for portioning and, respectively, or kneading dough, comprising a drum stepwisely rotatable around a horizontal axis and provided on its periphery with receiving openings for dough portions, at least one treatment member for the dough, a piston in each receiving opening guided within the receiving opening in radial direction of the drum, and a curved restricted guidance for the pistons for radial inward and outward movement of the pistons during at least one phase of the treatment, which restricted guidance guides the pistons inwardly and outwardly, with respect to the radius of drum and is automatically adjustable relative to the drum at least in the phases of stillstand of the drum motion.
Such apparatus are known (for example AT-PS 341 970). Generally they have four rows of receiving openings distributed in equal distances around the periphery of the drum, that means always displaced with respect to each other for 90.degree.. The stepwise advance of the drum causes a rotation of the drum for 90.degree. per step, so that the receiving openings are conveyed from station to station, where the treatment of the dough takes place, for example portioning or kneading. Within the above mentioned known apparatus, a portioning station is disposed at the one side of the drum, at which station the dough is pressed into the receiving openings by means of a pusher member and is portioned by a shearing edge when the drum moves again. Within the region of the summit of the drum a kneading station is provided at which a kneading tool ist disposed that kneads the dough pieces accommodated within the receiving openings into a ball-like shape. At the other side of the drum a deposit station is disposed at which the dough pieces are ejected from the receiving openings by an outward movement of the pistons. This outward movement of the pistons is obtained by the restricted guidance of the pistons which is rotated relative to the drum during the stillstand thereof, the curvature of this restricted guidance effecting the desired outward movement of the pistons at the deposit station. At the same time, during this relative rotation of the restricted guidance, the pistons are retracted at the portioning station, in order to suck-in the dough which has to be pressed-in into the receiving opening. Also at the kneading station a retraction of the pistons takes place during the kneading process, in order to consider that the dough piece requires more and more space during the kneading process. The known apparatus works without any problem as long as the distances for which the pistons are moved forwardly or, respectively, backwardly at the single stations, are not changed for a too great extent. Such a change, however, is necessary at the portioning station, if the dough piece to be weighed there has to be changed with respect to its volume or, respectively, weight, that means, that for example, one must change from the production of smaller dough portions to the production of bigger dough portions or vice versa. For this, it is indeed known from the initially described construction to additionally adjust the restricted guidance relative to the drum by means of an adjustment device, that means, as it were, to change the starting position of the relative movement between restricted guidance and drum. Thereby, at the portioning station a more or less long retraction of the pistons can be adjusted at choice. However, difficulties arise, if this adjustment should be made to a comparatively large extent, because then a considerable change of the said starting position of the restricted guidance is necessary. This change influences the circumstances at the kneading station and at the deposit station so that there the optimal positions of the pistons during the kneading process cannot more be obtained or, respectively, the dough pieces are no more reliably ejected from the receiving openings.
The invention has at its object to improve an apparatus of the initially described kind so that the circumstances at one station can be changed at choice for a large extent without influencing the other stations. The invention solves this task by the features that the restricted guidance comprises at least two curved path sections provided on at least two members that are adjustable relative to each other and effectively complete each other to the common restricted guidance. By this, the above described problem is solved with simple constructive effort. The parts of the restricted guidance disposed on the single elements further guide the pistons always so that these pistons cannot swing neither inwardly nor outwardly, so that they are always guided exactly. Nevertheless, by the adjustment of the single members relative to each other it can be obtained that changes of the restricted guidance are possible at the single stations without that the guidance effective for the other stations is also changed. Thereby, a wide field of variations is possible to adjust the conditions of treatment at the single stations at choice, for example, at the portioning station the weight or, respectively, the volume of the dough pieces to be portioned can be changed to a large extent without that this change influences the kneading process or the deposition process of the dough pieces.
As a rule, two members are sufficient, the relative position of which can be varied, however also more than two such members may be provided, for example, such a member may be allocated to each one of the three said stations. However, if portioning, kneading and deposition of the dough pieces should take place at one single drum, the principle is retained that at the portioning station the pistons are retracted, and also at the kneading station, whereas at the deposit station the pistons are moved outwardly. Just so, always the general principle of function is retained that at least portions of the restricted guidance are moved during the stillstand of the drum in order to obtain these movements of the pistons.
Within the spirit of the invention there are several possibilities to obtain the relative adjustment of the single elements constituting the restricted guidance: According to a particular favourable embodiment of the invention, the arrangement can be such that at least two members carrying the curved paths are adjustably rotatable relative to each other around a common center. This results in a construction easy to survey and having a simple possibility for the drive. However, within the spirit of the invention, the embodiment can also so constructed that at least two members carrying the curved path are adjustably spreadable from each other at one side, thus substantially like the single sectors of a fan. Within this, in each case there is a simple possibility for the drive within the spirit of the invention by the fact that the members carrying the curved path are disposed on shafts or, respectively, hollow shafts concentrically bearingly supported in each other and rotatable relative to each other by adjustment means. The amount of this rotation as well as the angular velocity can be chosen to enable one to adapt one to varying requirements. Thus, within the spirit of the invention the embodiment can be so chosen that the adjustment means comprise a cam rotated by the drive means and at its periphery being contacted by a rocker lever connected to the shaft of one of the members. The shape of this cam determines in such a case the amount and the angular velocity of rotation of the respective member. This enables one to obtain again changes of the piston movements occuring during the single treatment processes by exchange of the cam against a cam of different shape. In addition thereto, within the spirit of the invention the arrangement may be such that the drive means comprises a further curved path from which as well the stepwise advance movement of the drum as also an adjustment of at least one curved path of the restricted guidance are derived, the duration of each step of movement of the drum being shorter than the intervening intervals. Thereby, in the intervals of the drum movement, more time for the treating processes is obtained, what in particular for the kneading process is of substantial advantage, since the quality of the kneaded dough piece to a high degree depends from the duration of time being at disposal for the kneading process. Thereby it is also facilitated to adapt one to varying conditions .